How pollution and other environmental effects can affect human DNA

By now, most of us understand that we have a direct effect on our environment — but the environment can also have an effect on us. We’re not just talking about the way that storms, wildfires, and tectonic activity can affect human beings, we’re talking about how the environment can change your DNA.

But in order to understand aspects of our DNA are altered by the environment, we need to explore what environmental factors contribute to this change in the first place.

Can the environment change your DNA?

To clarify, it is not our DNA gene sequences that are affected by our environment, but our gene expression. Gene expression refers to the way genes function, not the way genes are. Duke Magazine likens this to a computer: DNA is the hardware, gene expression is the software that decides how that hardware operates, and the environment can affect the way that software programming works.

According to Duke, gene expression can be altered by several environmental factors including food, drugs, or exposure to toxins or pollutants. These changes can be slight and might not have any noticeable effects, but they can also be dramatic. In cases where the gene expression is altered immensely, certain important genes within our DNA could be turned on or off at times when they are supposed to be the opposite way.

What’s more, these alterations in gene expression can be passed on from parent to child and onwards down the line, genetically. Take for instance the case of a Dutch family who survived a World War II era famine. The survivors’ grandchildren evinced the same changes caused to their DNA by extreme hunger as the survivors themselves experienced in the 1940s, as per Duke.

Gene expression is controlled by chemical switches called methyl groups within the genes themselves. If methyl groups are added, a gene turns off, if they are taken away, and demethylate, the gene is then turned on. This on and off action can effect the way our bodily functions react and cause negative effects on our health.

What environmental factors affect DNA?

Our bodies are affected by a number of external environmental factors. Pollution tends to have the most obvious and severe negative effects, but other factors can affect our DNA and gene expression, which, in turn, affect our hormones and metabolic processes. According to Scitable, light and temperature can affect us as easily as drugs, food, and chemicals.

We aren't alone in this, either. Environmental factors affect animals as easily as they do humans. As explained by Scitable, certain breeds of Himalayan rabbits can experience changes in fur, skin, and eye pigments when temperatures warm or cool. These changes can happen in individuals and across generations if temperatures remain constant.

The point is, the world we live in has a very serious affect on our genetic development. As things get colder or hotter, species like ourselves are going to have to physically adapt to those changes. Those changes could affect the way we reproduce, the way we look, or the way our bodies work.

It seems as though our best bet to avoid potentially dangerous changes to our DNA would be to eschew pollutants and mitigate climate change in such a way that we can reclaim a global homeostasis. Then again, if life is change, perhaps ours will inevitably lead us to be more suited to the world we are creating for ourselves.